I am a research scientist with a substantial background in cell and developmental biology research. I also have significant experience with live cell imaging, particularly of embryonic development. I would like to extend that expertise to include the analysis of stem cell dynamics. My immediate goals are to gain the necessary training to conduct research on the mechanisms used by embryonic stem cells (ESCs) as they differentiation. My long-term goal is to develop an independent research program emphasizing live cell imaging to investigate the processes of developmental decision-making in a variety of model systems, including ESCs. This current application includes a career development plan consisting of didactic course work, workshops, seminars and hand-on training. I am fortunate to be at the University of Wisconsin- Madison, which has a history of strong support for stem cell work and has a thriving program of stem cell research and training opportunities. In this application, I propose to apply the advanced imaging technologies of multiphoton spectral and lifetime imaging microscopy, as have been used to characterize metabolic changes during cancer progression, to characterize the fluorescence properties of ESCs in different stages of cardiac differentiation in order to determine "signatures" of endogenous fluorescence that could be used to non-invasively identify those stages in living ESCs. The first two parts of my research plan will be performed with mouse ESCs while the final part will be performed with human ESCs. Not only will the proposed research generate important data about changes in the metabolic status of ESCs during differentiation toward a cardiac fate, this plan is also designed to provide me with a training that will encompass a wide range of ESC techniques, effectively broaden my knowledge base of ESC biology, and will provide a foundation for my future studies. Relevance: Embryonic stem cells have the exciting potential for clinical applications, including the repair of damaged heart tissue. To maximize the utility of embryonic stem cells for such therapies, and to assess potential of such therapies, it is necessary to understand .their basic biology. The aim of this proposal is to better understand changes that occur as embryonic stem cells become heart cells. (End of Abstract) [unreadable] [unreadable] [unreadable]